Loops

In this class, we will delve into loops, which are structures that allow a block of code to be executed repeatedly until a condition is met.

Types of loops Link to heading

  • while loop: It is executed while a condition is met.
  • for loop: It is executed on a sequence of values.

while loop example: Link to heading 

number = 1

while number <= 5:
    print(number)
    number += 1

Exit: Link to heading 

1
2
3
4
5

In this example:

  • The while loop is used to print the numbers 1 to 5.
  • The variable number is used as a counter.
  • The condition number <= 5 is checked before each iteration of the loop.
  • If the condition is met, the code block is executed within the loop.
  • If the condition is not met, the loop ends.

for loop example: Link to heading 

name_list = ["Ana", "John", "Peter"]

for name in name_list:
    print(name)

Exit: Link to heading 

Ana
Juan
Pedro

In this example:

  • The for loop is used to loop through a list of names.
  • The name variable is used to store each name in the list.
  • The loop is executed once for each name in the list.

break and continue statements: Link to heading

  • The break statement is used to break out of a loop before it ends.
  • The continue statement is used to move to the next iteration of the loop without executing the rest of the code.

Example: Link to heading 

number = 1

while True:
    if number % 2 == 0:
        number += 1
        continue
    print(number)
    number += 1

    if number == 11:
        break

Exit: Link to heading 

1
3
5
7
9

In this example:

  • The while True loop is used to create an infinite loop.
  • The statement if number % 2 == 0 checks if the number is even.
  • If the number is even, the number variable is incremented and the next iteration of the loop continues without executing the rest of the code.
  • If the number is odd, the number is printed and the number variable is incremented. The statement if number == 11 is used to exit the loop when the variable number is equal to 11.
  • The continue statement was used to skip printing even numbers.

Exercises Link to heading

  • Write a Python code that calculates the sum of the numbers from 1 to 100.
  • Write a Python code that prints the even numbers from 1 to 10.
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